New deepwater drilling rigs extend search for energy

BRETT CLANTON, Copyright 2010 Houston Chronicle |
April 9, 2010

A supply vessel cruises near the Discoverer Inspiration in the Gulf of Mexico. The huge ship is nearly as big as an aircraft carrier and built to operate in waters up to 12,000 feet deep and drill wells another five miles below the sea floor.

Photo By Melissa Phillip:/Chronicle

Ray Pittman controls the main drilling functions from a cyber chair on Discoverer Inspiration.

SOME oil and gas industry leaders like to say the “easy oil” in the world has been found. But perhaps the only way to fully appreciate that idea is to step aboard a ship like the Discoverer Inspiration.

The $630 million vessel is one of a new wave of ultra-deepwater drilling rigs, leaving Asian shipyards now, that will again push the limits of what the offshore industry can do.

Nearly as big as an aircraft carrier, the Discoverer Inspiration is built to operate in waters up to 12,000 feet deep and drill wells an additional five miles below the sea floor. Think of flying in an airplane at 40,000 feet and trying to stick a 7-inch-wide pipe in a car on the ground below, and you get the idea.

Though a previous generation of ships could reach almost as far, the Inspiration has added more power, speed and automation to the drilling process, as well as more ways to track in real-time what is happening in the well so operators can correct problems as they go.

“If you can cut that by a quarter or a third or even half, there's huge, huge improvements in the economics, which would bring some discoveries in that in the past would be considered uneconomic,” he said.

Oil companies are demanding such rigs as they expand their search for oil and natural gas into deeper waters of mature basins like the Gulf of Mexico and eye emerging regions such as the Philippines and East Africa.

Today, there are 128 rigs in the world capable of drilling in at least 4,000 feet of water, and most reside in the U.S. Gulf of Mexico, Brazil and West Africa, said Tom Kellock, head of consulting at ODS-Petrodata in Houston. An additional 67 rigs are planned, on order or under construction, though 27 have still have no contract with oil companies, he said.

But they don't come cheap. Chevron is paying Switzerland's Transocean, which has major operations in Houston, about half a million dollars a day under a five-year contract for the Discoverer Inspiration. Total costs to run the rig come in closer to $1 million a day.

Aboard the Discoverer Inspiration, it's easy to see how the tab can escalate quickly in the deep water.

The ship requires a cast of nearly 200 people to keep the operation running. Six 9,000-horsepower diesel engines — each capable of consuming 250 gallons of diesel per hour — run generators that create enough power to keep the lights on in a city of 42,000 people. They also run six rotating satellite-guided propellers that keep the ship almost perfectly still while drilling, eliminating the need for anchors.

Even drilling fluids, which lubricate drill bits and remove debris from the well, can run $10 million per well.

Such costs are easier to swallow now that oil prices are moving toward $90 a barrel again, but operators say the projects are planned over years and not subject to short-term moves in commodity prices.

Steven Newman, CEO of Transocean, said next-generation vessels may not look much different than those launching today. But he envisions further advances in the integration between what the drill bit is seeing downhole with instrumentation on the ship's drill floor. The end result, he said, should be a more efficient well.